Figure 10: (a) Zero-field-cooled and field-cooled magnetic susceptibility, , of powdered Fe3Sn2. Upon cooling below the Curie temperature, K, the moments order ferromagnetically along the hexagonal -axis. Below K, the moments then rotate into the -plane. During this transition, the moments become noncollinear, shown by the gradual increase in . The broad maximum at K indicates a transition to a spin glass state which coexists with an ordered ferromagnetic moment now lying largely in the -plane, taken from . (b) Field-dependence of at various temperatures. The dependency is similar to that observed for . The large room temperature saturated value of 3.2 cm demonstrates the potential for geometrically frustrated ferromagnets as materials for spintronics devices, taken from .